Facsimile recorder



Feb. 6; 1945. A, B AIN- 2,368,739

FACSIMILE RECORDER Filed Jan. 30, 1941 2 Sheets-Sheet l Feb. 6, 1945. A.BLAIN 2,368,739

FAGSIMILE RECORDER Filed Jan. 30, 1941 2 Sheets-Sheet 2 I I l I l .l

l. 1 l I I I I I I l I. I I l .I I r I Patented Feb. 6, i945 I 2,368,739mosmmn mzconpsa Albert Blain, Philadelphia, Pa., assignor to RadioCorporation of America, a corporation of Delaware Application Januaryat, 1941, Serial No. 376,616

2 Claims.

more particularly to facsimile recorders.

In facsimile systems wherein a drum having a helical edge is adapted torotate in synchronism with a drum supporting the record to .betransmitted, the record may be reproduced on a record surface by causingthe helical edge to act upon the surface in accordance with the signalsreceived from the facsimile transmitter.

One method of reproducing records by facsimile consists in impregnatingpaper .by a substance which will he discolored under the influence of anelectric current and to apply this current at single small areas of thepicture surface at a time, causing said area to progress systematicallyover the paper and so varying the current that, at each position of thearea, it is proportional to the degree 'of darkening necessary toreproduce the record.

In my copendlng application Serial No. 376,615,

filed Jan. 30, 1941, I have described a method of recording whichincludes a pair of adjacent drums provided with helical electrodes whichintersect on a recording surface. By applying a, signal to the helicalelectrodes and maintaining one of the electrodesmore positive than theother, a record may be made on a surface adjacent the more positiveelectrode.

According to this invention, at least two spiral electrodes are suppliedto each of two adjacent drums which are adapted to revolve about twoparallel axes, such that one electrode on each drum provides a recordingspot with its corresponding electrode of the other drum. By maintainingone electrode of one drum positiv with respect to its correspondingelectrode on the sec- 'ond drum, and maintaining the second electrode ofthe second drum positive with respect to its corresponding electrode onthe first drum, a record may be made. on 'both sides of a sheet passedbetween the two drums by applying a signal to each set of electrodes.

The primary object of this invention is to provide a facsimile recorderadapted to record on both sides of a'sheet.

Another object of this invention is to simultaneously record a pluralityof facsimile signals. Other and incidental objects of the invention Iwill be apparent to those skilled in the art'from a reading of thefollowing specification considered in connection with the accompanyingdrawings in which Figure 1 isan end view of a facsimile recorder,

Figure 2 is a sectional view of Fig. 1,

p v (Cl. 234-59) This invention relates to facsimile systems and Figure3 is a schematic front view showing the printer drums and the helicalelectrodes,

Figure 4 is an end view of the printer drum,

Figure 5 is a sectional view of the printer drum, and

Figure 6 is a plan view of the facsimile recorder.

Referring to Fig. l, a spool I carries a roll of paper or otherrecording surface 3. Below the spool I, a tank 5 is provided with aguide roller 1 under which the paper 3 from the spool I is passed sothat it will be immersed in a tank '5 containing a liquid adapted tosensitize the paper 3 and cause its color to be changed upon theapplication of an electric current. This may be accomplished by meansand methods such as shown and described in Zworykin Patent 1,909,142,patented May 16, 1933.

The paper 3 then passes up and over a stationary guide tube 9 rotatablymounted on a shaft l0, under a guide rod II and between the drums l3andli. Drums l3 and I5 are composed of a non-conductive material. DrumI3 i provided with spiral electrodes l1 and i8 and drum l5 with spiralelectrodes l9 and 20.

The paper 3 then passes under the guide rod 2| and over the drive roller23 and between the drive roller 23 and the pressure roller 25 which isforced against the drive roller 23' .by the spring 21.

Drum l5 and gear 29 are mounted on the shaft 33; Drum l3 and gear 3| aremounted on shaft 32. A gear 33 mounted on shaft l0 engages the gears 29and 3|.

Fig. 2 shows a guard member 35 which covers the drum l3 whereby thespiral electrodes l1 and I3 are guarded from mechanical damage and theoperator is protected from receiving an electrical shock from theexposed and charged'helical elec- Fig. 3 shows a front view of the drumsI3 and IS. The similar helical electrodes l1 and I8 are supported uponthe surface of the drum l3. The

electrodes l1 and I8 are spaced from each other on the surface of thedrum l3. The electrodes l9 and 2|] are similarly supported upon thesurface of drum l5. It will be noticed that each electrode intersectsits corresponding electrode on the adjacent drum. Thus, electrode [1intersects the electrode I9 and electrode l8 intersects tact between theassociated helical electrodes will move from one end of the drums to theother end of the drums. As each point of intersection approaches oneedge or the paper, which is interposed between the printer drums, thesame electrodes will intersect again at the other edge of the paper.

If it is desired to have the drums rotate in opposite directions, it isnecessary that the electrodes on one drum curve around their associateddrum in a direction opposite to that direction which the electrodes ofthe other drum curve around their associated drum.

If a signal is applied between the electrodes i1 and I9, and theelectrode I1 is maintained positive with respect to electrode I3, arecord in accordance with the signal will be applied to the surface ofthe sheet'adjacent the positive electrode H or upon the upper surface ofthe sheet. If a second signal is applied between the electrodes l8 and20, and in this case electrode 2|] of the lower drum I is maintainedpositive with respect to its associated electrode I8, the record willappear on the lower side of the sheet adjacent the more positiveelectrode 20. Thus, it follows that records may be made simultaneouslyon both sides of the sheet.

Fig. 4 shows an end view of the printer drum and shows in more detailthe slip rings 31 and Each of the slip rings 31 and 39 are connected toone of the spiral electrodes on its associated drum.

Fig. 5 shows a sectional view of the drum and indicates one method inwhich the cylindrical electrodes I1 and I8 may be attached to theprinter drum i3 and to their associated slip rings 31 and 39,respectively. The screw 4| makes con tact with slip ring 39 and themetallic member 43 into which the screw 45 is engaged to support theelectrode IS. A screw 41 supports and connects the electrode 31 to themetallic member 49 into which the screw 5| is engaged to support theelectrode I1. The two metallic members 43 and 49 are insulated from oneanother by the insulating strip 53. At the end of the drum opposite tothat end on which is mounted the slip rings, there is provided a pair ofmutually insulated metallic members 55 and 51 which support the otherends of the electrodes 18 and I1, respectively.

Figure 6 shows the paper and drum drive mechanism. A motor 59,maintained in synchronism with the motor at the facsimile transmitter,is Y mechanically coupled to the shaft l0 upon which The lower gear :9drives the drum l5 which is.

fixed to the shaft 30 upon which is mounted a worm gear 6| which engagesthe gear 63 mounted on the shaft 62 supporting a worm gear 53 which, inturn, engages the gear 65 on the shaft including the sheet drive roller23.

As the paper is passed through the solution contained in the tank 5, itis sensitized so thatif an electric current is passed therethrough, amark will appear at the point of contact and on the side adjacent theelectrode charged positively with respect to its correspondingelectrode. The paper thus sensitized passes between the drums l3 and [5which are rotating in directions shown by the arrows'at the samepredetermined rate.

The terminals or brush members 69 and 10 are adapted to make contactwith the slip rings 31 and 33, respectively, so that the incomingsignals may be applied to the electrodes l1 and IS. The lower drum 15has a set of similar electrodesbo cooperate with its slip rings forcontact during movement of the drums. This is not shown on the drawings.

A transmitter adapted to transmit facsimile signals of the type whichmay be recorded by a recorder improved in accordance with this inventionis one such as shown and described in an article entitled "Facsimiletransmission and reception by Maurice Artzt in the Electrical EngineersHandbook. A recorder designed in accordance with this invention isadapted to record two signals such as can be transmitted by such afacsimile transmitter.

Such a signal is applied to each set of electrodes and as the paperslowly moves between the rotating drums l3 and IS, the point ofintersection between the paper and the associated electrodes scans thepaper from one side to the other and forms a continuous image on bothsides of the paper, each image being representative of its respectivetrain of facsimile signals.

While one system for carrying this invention into effect has beenindicated and described, it will be apparent to one skilled in the artthat this invention is by no means limited to the particularorganization shown and described, but that many modifications may bemade without departing from the scope of this invention as set forth inthe appended claims.

I claim as my invention:

1. In a facsimile recording system, the combination of a pair ofadjacent drums adapted to rotate about parallel axes and each of whichsupports a plurality of mutually insulated helical electrodes, means forfeeding a record receiving sheet between said drums and in contact'withadjacent points on corresponding electrodes of each of said drums, meansfor applying a signal representative of a record to be reproducedbetween an electrode on the first of said drums and a correspondingelectrode on the second of said drums, and means for applying a secondsignal of opposite polarity to said first mentioned signal andrepresentative of a second record to be reproduced between anotherelectrode on the first of said drums and a corresponding electrode onthe second of said drums.

2. In a facsimile recording system, the combination of a pair ofadjacent drums adapted to rotate about parallel axes and each of whichsupports a plurality of mutually insulated helical electrodes, means forfeeding a record receiving sheet between said drums and in contact withadjacent points on corresponding electrodes of each of said drums, meansfor applying a signal of a given electrical characteristicrepresentative of arecord to be reproduced between an electrode on thefirst of said drums and a corresponding electrode on the second of saiddrums, and means for applying a second signal having an electricalcharacteristic which differs from the electrical characteristic of saidfirst mentioned signal and representative of a second record to bereproduced between another electrode on the first of said drums and acorresponding electrode on the second of said drums.

I ALBERT BLAIN.

